Testing the weapon

Wiki Weapon

The parts for the Liberator are almost completely 3D printed. The only nonplastic components of the weapon are the firing pin -- a standard metal nail -- and a six-ounce piece of steel whose function is to make the gun spottable with a metal detector. (The U.S. Undetectable Firearms Act, which is set to expire at the end of 2013, prohibits weapons that don't set off a metal detector.)